Desirable p vh le been achieve and have bue (here HEU and LEU " Iu4W tv S190)

2

HTR fuel: main criteria quantified .mW

Manufacture burn-leach on particles burn-leach on fuel body

Irradiation in-pile R/B PIE shows ... and ...

"< lx1O-6

"< 6x10 5-

Heating shows F(85Kr) < 2x10-6 *

and F(137Cs) < 2x1O-4

" Necessary, but not sufficient

11

<< lx1O-6 *

F(137Cs) < 2x10F( ll mAg) < 2x10.3

Every fuel element in an irradiation experiment is contained in an isolated cell.

Temperatures are closely controlled by adjusting the He/Ne ratio in the purge gas

which also allows the on-line determination of the fission gas release rate.

Thermocouple Purge gas pipe Radiation shields

Graphite cup

Test fuel element

13

1'�

I

A

I I I I I 1�

x

CM

II

Iv'U I,

C) 0

qq

I S. rn

I I a0

a

7 I -I

'1 C 0

I I I

ti4l! I

10

A

E U)

0 cj (D) =3

FL

8

6

4

2

0

0

HFR-P4

AVR LEU TRISO .•FRJ2-P27

R2-K13J2-1

FRJ2-K13 FRJ2-K15 - • I --- l

5 10 15 20 25

Bumup (%FIMA)

The main parameters in fuel irradiation testing are heavy metal bumup and accumulated fluence of fast neutrons. Irradiation temperature, perhaps the most important parameter of an, is usually around 10000 in the tests shown here.

17

Criteria for irradiation testing in order o relevance

* Temperature ° Burnup ° Fluence * Power/temperature gradients ° Transients * Real time

18

8 X10-6

85C0

1Tthelvebo#f#wionmgas is

in i t~ Lfr h Cycleuwaimm' katIIhmL Ke, he4 X1O-6

rgmh Paf e~w I*Ith mftes of

"AR asid aialft etefwith wmduim I W!I6O f uel s

2 X10-6

FortSt Vmin JNwh', ThAo TiOW

1976-88 11969-88& 1978-ý81 1982-89 19

Forschungszentrum JMlich

Source tevms for fiss•on products. into the primary circuit of

(i) heavy-metal contamination; (ii) particle defect and/ or failure; $i4) release from intact particles.

Sequence

an HTR are:

of F13 - is- 95 137Cs' 134Cs, 85Kr, 90Sr, l06Ru, Zr

Forschungszentrum Julich

Contribution to Fission Pr Somurce Terms

Observations:

Measurement Technologies

Free heavy metal

fraction

(D broken par•icle

fractiondefect SC/ wek Pkirtide 1fraclion

Difsive releasc conftritbuo

Manufacture Acid leach, weak irradiation, Bum-leach TRIGA furnace hot chlorination

Irradiation: in-pile R/B (Kr, Xe isotopes)

Irradiation: PIE cold gas release ? F(Cs,...), hot Cl F(Ag, )

Accident F(Ag) condition testing F(Cs) F(Kr) F(Cs, Sr,..)

F(Kr) delayed by diffusion through PyC

Brussels ; 2 ý:ebraayv 2001 peff

400I I I I

100 200 300 400

I

100 200 300 400

Irradiation time (full power days)

Gas release and temperature during irradiation of experiment HFR-K3

20

HFR-K3/1

OD

CO

Mr

10-2

10-4

HFR-K3/2,3 HFReKufc

.lei

L4here surface

..-7 I

10-6

10-8

140C

120C

1 000

800

Sphere surfaceCO

E W)

0 100

- Sphere suraceW _ ---, i.-•. ---- -

200 300

W 26I I I 5 1:00 200 300 400 500 600

l~o

10-2

10-4

100 200 300 400 500

Irradiation time (full power days)

Gas release and surface temperatures in experiment R2-K13 21

R2-K13/4

Sphere surface

C' CO

10-6

10-8

1400

100

E a) 80

0

S�d�YW600

Sphere surtace

A

L

)-

Temperawes im R2-KU3

Radial distribution of irradiation temperatures (time average) of R2-K13 test and during 1600 °C

heating test

1400

130

1100

-30 -10 0

Distance from sphere centre (mm)

22

10 20

0 5 10 15 Bumup (%FIMA)

* Xe1 33 0OKr85m *Kr88 <>Xe135 A KfO7' I I I I W

The release rate of short-lived fission gases, RIB, as a function of bumup in an ongoing irradiation experiment in the Jelich DIDO reactor (FRJ2-K15, 5 us from June 1989). The spikes in RIB have been measured during +2000C tmiqperabl transientL. The slow increase in RIB is an artifact of the birthrate calculation for 16.7% enrdched uranium, while the actual release is from uranium contamination of natural endichmentL

23

Irradiation to near 15 % FIMA

1400

a)

0~

E (D

0 100 200 300400 100 200 300 400

Irradiation time (full power days)

100 200 300

-4-400

24

I

Processing of fuel elements in the Hot Cells, e.g. during gamma spectrometry for burnup determination

Bumup bt-xr,•-ts CrossSection of the Hot Coll with the GanmMaetrumetrle Equipment

15

*Test rigs, *Neiar complete-rt re4x, 8% -e

up to 25000C *Cold fin ger KUFA

a Meas~wernient -tecnMnael-ltD~y for fuel cvite-ia

31

Sweep gas circuit of cold finger apparatus (KUFA).

32

"

0

EvacuaedM _- - Helium l~lul

cold linger lack

Water cooled - cold finger

--_ Tantalum ge, cylinder

f -~ Replacable .. -. condensate plate

Tantalum heater

i-pherlcal fuel element

Optics for .. - - pyrometric measurements

"- .... Heat reflector sheathing W/Re-Thermocouple

Helium outlet A.

Electrical connection Helium Inlet Vacuum pump ducts

Heating furnace used in accident simulation tests with irradiated spherical fuel elements (KOFA).

33

Sliding valve

Box floor

Pee-outA frma1mkus of KIJFA --mmmvi cold, mw

F-

plate Ta-tube Furnace

Released Fraction .Cs, 1lAg Sr .0.7 0.2 0.02 0.8 0.3-

7>1000C

36

...I.. ....... - ..

4Cl '8'

I

Fission products Cs, Sr, I are radiologically significant because- unlike the fission gases - they can be incorporated in the human body.

Important fission products

ELEMENT ISOTOPE

Solid fission products

Cesium4

Strontiumrn Iodine Fission gases

Krypton Xenon

13 7 Cs

13 4 Cs

9OSr 1311

30 years

2 years

29 years

8 days

"1Kr 11 years 5 days1 33Xe

HALF LIFE

35

Sequence of fission product 110mAg, 13 7 Cs, 1 3 4 Cs, 8 5Kr, 9oSr,

oU)

C13

C

0

15

release is 106 Ru, 95Zr

Temperature (0C)

Here the fractional release during temperature ramp to 26000C

[GA data, from Fig 4-39, page 192 of IAEA-TECDOC-978]

37

a AA 74/17

IIwo

U-TIUSO AVIR70/19

AVR 70V18 7.1 % *Mi

136o I M0 1700 I=X 2100 2M 25M

Temperature (°C)

Gas roease during temperature ramp to 2500C.

38

16W 4� @ �

&

u - i ' 100 to 1000 h

Temperature I time correlation in standard isothemul ftsts&

39

/

-u ww

1500C

0 I

I

E 0 I-

1000

500

250 47'OC/h h 105MOC

(or kradhftm pwature)

lt5 h I3W0

j95 h0

Fractional Release

I -k

0

MOM

1~10C

LAI-Ang teat at 1606-2100) °C 1 1 1 .I

10-6

io-Z

0 100 4W0

I&p

0

E.

CV

Heating time (h)

Krypton release during tests with irradiated spherical fuel elements at 1600 to 2100 °C.

107.1

,tn

0

Heating time (h)

Caesium release from heated spheres as a function of heating times up to 500 hour

I,.

'U'

-2tC ILi___

CO (D

0

CO

00

41

XV -4-4-- A

N--:ý N

-a, 1, ý, "

26€

Fractional Release

Fractional Release

"24

0 2:

(a -4

CD

0

0

ii II El ~1

A100

(=•,, AVR 70133 (D1• Fi

__R ___2 K I,/41•77 1

K3/3 4 --ý

Heating Time (h) Heating Time (h)

Krypton release in isothermal heating tests. Cesium releese in itera hetn tss

-43

, it

9°Sr Fractional 09 0

release0

0

U=

I.

I.

I

IiA

Ag 11 Om-Fractional Release

5. (D

Ac. isL ji, TM

MEU

A A I i I -

3* 001

:3 mm-wd PWR L )o fuel X) F x I I x x xxx co Do ou

amcm K3

isse snoum -5--ouli3s pap

pw 300an at *qmq pw painseen a-owl', PnJ HA

owt.

After subtraction of contaminatft~n cornponents,

f ission prodmc"release -curves i nereas~systernatical ly

indkoatl~theV~opess of SIC dMWtbria~oftsrinr-g: heating.

Thivolbserto~n led to the devel~pmventlot the,, G ood In

NOW~iek abandoning the classioailappvoseeItof ýpressure

veseeItf~iure mnodeling/ diffusionatireIase prediction.

0)

'0 a)

E

1 0-2

10-4-

10-8-

EI11 L80000]

/ 137Cs

liomAg/

90Sr 85Kr Dsr

v

Heating Time (hours)10 1000

63

y

The Goodin-Nabielek model for Kr and Cs release predictions

100

Heating Time (h)

10 100

Heating Time (h)

1900 0C 1800 1700 0C 160000

,,__/_ _. YR22 K13/1

U/ ,HFK3,3,

so measurement /.- - model caicultion

1000

64

Observed fission product release sequence during ramp

03 106Ru r

95 V4 13c or^ / I .

""/102 _sK 8 5 Kr 10-1 /3C

1l0mA 0

~? 1O.2 85Kr

0

U0 LL 10-3-/-

Intact Without particles outer PyC

10-4 _ ------

S, . I I I I ._ 1700 2100 2500 2100 2500

Temperature (°C) Temperature (°C)

Typical fission product release profiles during linear temperature ramp. In both cases, -200 irradiated particles were heated to 25000 C. The left diagiaza shows intact particles, and the right diagram shows particles where the outer PyC layers had been removed.

Forschungszentrum JOlichn

TheGoodinNabielekModel.ppt 11

The Goodin-Nabielek Modelling Approach co bines the statistics of SiC degradation With the variati .f0S1C.thk-kness (=,,SiC mass)to predict simultanebIsly caesium and tubseq tent krypton release.

MEDIAN THICKNESS DEGRADATION1.

1.0 j- 1.I

SIMPLISTIC FREQ. FAILUiRE

~tm S'CTImE -,.=

MEDIAN DEGRADATION

MEAN

FREQ, AIUR THICKNESS FAILURE

AREANý

)(M sic TIME

MEDIAN OEGRADATiON

MEAN MORE-PRECISE FREQ. THICKN4ESS FAILURE,ý

prm SiC

TheGoodinNabielekModel.ppt 13

m I

GO~IDbIa~ Mordelling Appvmvhm

* S~iicn rwbidý amwomin raf k is tbmiWauam

R... gas constan

T .. heating temperature

0TM ~hc of SIC Islure d@Aw Wm-s Ce reeams

4) ... SiZ tfaiure fraction =Cs release fracio t ... heatingtirn mn... Weibufl modidus

0Diffus~on of Kr through outer PyC after SW failur

FKr M d 4 r-1 Fv~tq-f) dt

Fr... Kr release fraction from pauticles Fpyc... Kr ddiffsion fraction through ou ter PyC

M oichIS

TheC~oodiriNabieleki~odel .ppt 12

x

a

'U,

0

I

Ia 0 z

w 2: w 2: I2: I

0, w 9

LU

I LU I0 a-J LU 0 0

a a

I

I

aII

-c V

0

E I

4-I C 0 N

C

-c V

L.

0 U-

a I

- - - ; ~ ~2 ~UP * Q - S 36-

i

a I

a

0

-*1

0 0 0

Geedin-Nlabielek- Approach, with, SiC D'I. 10 A subsequent evaluation of about 20 heating tests by Goodin"K's ustdl the degradation rateIl

Fig. W9burngh to, 92 show the goodiaueement ith., 3oa1d mi~

84 D. T. Goofbi "usIMa Acaidoftf 908293(IELTR.1O)IseA

85 D.T. Good~n, "Aoddvatc Asiff '"

H. Nobiusadwe ) 'UWDRO dens"t , Pmma Coizf-hdaON,~t

by Sdw* and Wedcsxo bGodn for iiewf

lUN 0C heatingtest of spher~e FRJ2-K1/4.

w C)

HUiwinjt1me� �h)TheGoodinNabielekI~ode1 .ppt 23

*mdu' OAD~odi o.

-4 .OPA" 1n

-I,

C erman KemJ Migration data from tem. o be hiaher than.reomejded

amoeba line.

2000 1500I I

1000!

TEMPERATURE S700 600I I

"1O .-/T (K)

5000C

z uIJ

5:

L"A CD

z

M -ij uJ

J|. I

pbere Grenze (9.5%)

M" itteiwert

untere Grenze(95%)

/TRISO(kein deutticher Einflufl von D)

250 500 750 1000 ____ ____ ____ ___Ze t [d)

Abb. 6.10; Relative Silber-Freisetzuflg eines Partikels

aus dem Zentrum eines Brenne~el~emetes beim Durc'r'

lauf durch die zentrale Core-Region ('Regicr1 1)

eines HTR/K-Rsaktors

10

- .- -

/ I

4.0 10

10

10

//

/I

/

"WO *A o

I obere Grenze(95%)

IRS /~tewr

unter I /z(9% id

duc i zn l Coe-e ioen ( Regi n 195)

sies etu HH ineakos Benlmne emDac~

Diagram shows 11°mAg and 1 3 7Cs release fractions as a function oftemperatU

230-530 d irradiation tests as measured in post irradiation "examination work.

shown is end-of-life R/B(85mKr).

*F(Ag 11Om)

o F(Cs 134)

A F(Cs 137)

1 E+O

1 E-1

1E-2

1 E-3

1 E-4

1 E-5

1!E-6

1 E-7

1E-8

1. E-9700

Gas turbines are planned "for allI[odern Ht1 sthereforei we needto:

Re-analyse exiting data(i,,e.1tempratures and.Ag'ýreleass)

* Perform dedicated irradiation tests

"* Consider design/ material improve

ments

"* If al!else fails, redesign the HTR

25

CO

0)

0 LO

LL

0 R/B (Kr 85m) EOL

800 900 1000 1100 1200 :1300 1400700

I

I

26

A gwom COmpeise to a *Wm Idm p dirims - -wft Sm duibmi eohhen~t alo nS

as svmammeaded by IAEA TECDOC M8'T¶us pedwmuuie md Assuive predm br I

cooled mss"wmd using a 1he0v 10m~. t VI hmo - is ebvissbw

Aq-1 tOin Facboenal Rmle... Of Cemma, We Use Il muk MOMe

IEi

1 E-3

I E-4 ___________h arta

1 E-6 - Pedicted Partc~ leeu stbl I*A i gmam4i

0 MSS&Ned Fuel Eleffwit amterin to be .iessmd byl

0.01 0 1 1 10 MusitSn and is talm. ao~mfd to

/ Dt, the normakeed diffusmo tme of Ag win1"gI

Bumup (%FIMA)

20

Results from 74 irradiation Weft with U0 2 TRISO particles: "wo failures observed in a& coseso this was also assumed for HFR-EI up to 20% FIMAJ Shown are r

|95% confidence limit derived from the limited number of parOtice in the test

9 ____

9 4

10 is 20

I E-3

0

IZ I E-4

LL

I E-5

0--

S

B-M (%FR4A)

450,000

400,000

350,000

300,000

250,000

200,000

150,000

100,000

50,000

00 5 10 15

I E-2

ii

.o_..v-

I E:-6

-101 , "a-fica, of -dl- ON m Niifi --g:

A" Mn vme

Ratoad Irsericon Fuel Numnber Cowatefe puiir number data elemnfit of fe ilciml

tye onm Kemael C48*v

0 Jhjky66 UCC 30155 CKLQCI *471also 93%

1 Oct 68 T 7510 (MLb.C, HT1ISO 03%

3 Apr. 69 OK 1777 (mc, Kn iso. 93%

4 Juk 70 OK 6210 (NMI~C newIS 93%

5-1 Nov. 70 OK 25970 (MhULCS , *0153 93%

S-2 DeC.71 001 20825, M RD 2

7 Jan. 73 001 7840 ChO0, *4719180 93%

6-1 OCI.73 001 11000 (MhL40, Kfl51so 92%

6-2 Dec. 73 0121 2446 WE, 1119130 15% I WE LIT 5150 0.7%

8-1 May 74 OPBI 1440 U02 1880 -93%

8-2 May 74 OF02 11191-80

7110 1115180O 9 Sep. 74 ThTR-1 5145 (Th.Lb, 097180 93%

10 Dec. 74 THflR.2 10000 mku.Lo, Kfl 513 93%

, 1I D e c .7 4 T H T R .2 5 0 0 W T h o,L 0 * 1 5 1 9 0 9 3 %

12 Mar.76 001 11325 cmulWo, ff09180 93%

14 Nov. 76 001 093 (MTh,U0 Kn7 5130 93%

13-1 Dec. 77 OFE13 6077 LICE LM TRISO 90%

13-3 Dec. 77 OFUS mu5 0C LlTMIS 92% WEO LiiTRIS

13-2 July80 OF84 5881 UCt il TASO 9D% Tho, 1,18190

is Feb. 81 G02 6087 (ThU)0, IT! TRISO 93%

18 July81 003 11547 (MhU), *ff l 519 93%

19 July82 0123 24815 UIO, ITITRISO 10%

21 Feb. 84 0124 20250 UJO, ITI TRISO 17%

20 Oct 85 002 11854 (TWO,IO LilTRISO 93%

22 Sep. 86 THTR 1522 (Th,LQ0, 11BISO 93%

21-2 Oct 87 0124 8740 UO, LTITRWS 17% sum 28789 29

Suggested HTR fuel work, to be discussed:

(i) 11°gAg: Re-evaluate release data during anual operations for better source term data base in direct cycle applications.

(ii) Determine influence of burnup > 10%FIMA on irradiation performance, in particular for potential reduction of 16000C capability.

(iii) Analyse accident condition performance > 1600°C for an improved coated particle model.

Confidence lo

a HTR is alive again-more so tha ever before

* Good international basis "* Fuel manufacture in Britain, US,

Germany, Russia, Japan, China

" Complete irradiation qualification in Germany; many test results from USA, UK, Japan, Russia, China

" Extensive results from core heatup simulations testing in Germany, USA, Russia and Japan

66

* Irradiation and core heatup testing in European HTR program filghb"urnup• and >1 600°C]

S.Experiment- plannirng•and va:-Vaion- in cooperation with PBMR ih* SoUthiAfrca

* German support in SouthlAfrican fuel manufacture

* US-German proposals.. - international irradiation test, R.lE analysis - model development and.-a Ppiations

67